How to Safely Evaluate Mathematical Expressions in JavaScript Without Using `eval()`?

Evaluating Mathematical Expressions in JavaScript Without Using Eval()

Evaluating mathematical expressions without resorting to the potentially dangerous eval() function is a common task in JavaScript programming. To address this, let's explore a couple of alternative solutions.

JavaScript Expression Evaluator

The JavaScript Expression Evaluator library provides a convenient way to parse and evaluate mathematical expressions. It allows you to specify expression strings and use variables to customize the evaluation. For example, the following code evaluates the expression "2 ^ x" with x equal to 3:

const result = Parser.evaluate("2 ^ x", { x: 3 });

Math.js

Math.js is another popular JavaScript library for mathematical operations. It includes a powerful expression parser that supports a wide range of mathematical functions. Like the JavaScript Expression Evaluator, it enables you to pass variables and evaluate expressions dynamically:

const result = math.eval('sin(45 deg) ^ 2');

User Recommendation

Another user has suggested a response on Stack Overflow that utilizes the evalx() function to evaluate mathematical expressions safely. Here's a snippet from that answer:

function evalx(expr, scope) {
  return Function(`'use strict'; return (${expr})`)()(...scope);
}

By calling the evalx() function, you can evaluate expressions without the security risks associated with eval().

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